/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Exoffice Technologies. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Exoffice Technologies. Exolab is a registered
* trademark of Exoffice Technologies.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2005-2006 (C) Exoffice Technologies Inc. All Rights Reserved.
*
* $Id: DefaultConnectionPool.java,v 1.9 2006/12/16 12:37:17 tanderson Exp $
*/
package org.exolab.jms.net.connector;
import EDU.oswego.cs.dl.util.concurrent.ClockDaemon;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exolab.jms.common.threads.ThreadFactory;
import org.exolab.jms.net.uri.URI;
import org.exolab.jms.net.util.Properties;
import java.security.Principal;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Manages a pool of {@link ManagedConnection} instances, for a particular
* {@link ManagedConnectionFactory}.
*
* @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
* @version $Revision: 1.9 $ $Date: 2006/12/16 12:37:17 $
* @see AbstractConnectionManager
*/
class DefaultConnectionPool
implements ManagedConnectionAcceptorListener,
ManagedConnectionListener, ConnectionPool {
/**
* The connection factory.
*/
private final ManagedConnectionFactory _factory;
/**
* Invocation handler to assign to each new connection.
*/
private final InvocationHandler _handler;
/**
* The connection factory for resolving connections via their URI.
*/
private final ConnectionFactory _resolver;
/**
* The set of allocated connections.
*/
private List _connections = Collections.synchronizedList(new ArrayList());
/**
* A map of ManagedConnection -> ManagedConnectionHandle. The handles are
* used to reap idle connections.
*/
private Map _handles = Collections.synchronizedMap(new HashMap());
/**
* The set of connection acceptors.
*/
private List _acceptors = Collections.synchronizedList(new ArrayList());
/**
* The set of accepted connections.
*/
private List _accepted = Collections.synchronizedList(new ArrayList());
/**
* The set of all connections, as a map of ManagedConnection -> PoolEntry
* instances.
*/
private Map _entries = Collections.synchronizedMap(new HashMap());
/**
* Reap thread synchronization helper.
*/
private final Object _reapLock = new Object();
/**
* Clock daemon for periodically running the reaper.
*/
private ClockDaemon _daemon;
/**
* Interval between pinging and reaping connections, in milliseconds.
* If <code>0</code> indicates not to reap connections.
*/
private final long _reapInterval;
/**
* Iterations before a connection that hasn't responded to a ping
* is declared dead.
*/
private final int _reapDeadIterations;
/**
* The maximum period that a connection may be idle before it is reaped,
* in milliseconds.
*/
private final long _idlePeriod;
/**
* The caller event listener.
*/
private volatile CallerListener _listener;
/**
* Property name prefix for pool configuration items.
*/
private static final String POOL_PREFIX = "org.exolab.jms.net.pool.";
/**
* Configuration property to indicate the no. of reaps to wait before
* reaping a connection that hasn't responded to a ping.
*/
private static final String DEAD_ITERATIONS = "reapDeadIterations";
/**
* Configuration property to indicate the reap interval.
*/
private static final String REAP_INTERVAL = "reapInterval";
/**
* Configuration property to indicate the idle time for connections
* before they may be reaped.
*/
private static final String IDLE_PERIOD = "idlePeriod";
/**
* The logger.
*/
private static final Log _log
= LogFactory.getLog(DefaultConnectionPool.class);
/**
* Construct a new <code>DefaultConnectionPool</code>.
*
* @param factory the managed connection factory
* @param handler the invocation handler, assigned to each new managed
* connection
* @param resolver the connection factory for resolving connections via
* their URI
* @param properties configuration properties. May be <code>null</code>
* @throws ResourceException if any configuration property is invalid
*/
public DefaultConnectionPool(ManagedConnectionFactory factory,
InvocationHandler handler,
ConnectionFactory resolver,
Map properties) throws ResourceException {
if (factory == null) {
throw new IllegalArgumentException("Argument 'factory' is null");
}
if (handler == null) {
throw new IllegalArgumentException("Argument 'handler' is null");
}
if (resolver == null) {
throw new IllegalArgumentException("Argument 'resolver' is null");
}
_factory = factory;
_handler = handler;
_resolver = resolver;
Properties config = new Properties(properties, POOL_PREFIX);
_reapInterval = getPropertyMillis(config, REAP_INTERVAL, 60);
_reapDeadIterations = config.getInt(DEAD_ITERATIONS, 5);
_idlePeriod = getPropertyMillis(config, IDLE_PERIOD, 5);
}
private long getPropertyMillis(Properties config, String key,
int defaultValue) throws ResourceException {
int seconds = config.getInt(key, defaultValue);
if (seconds < 0) {
seconds = 0;
}
return seconds * 1000;
}
/**
* Creates a new connection.
*
* @param principal the security principal
* @param info the connection request info
* @return a new connection
* @throws ResourceException if a connection cannot be established
*/
public ManagedConnection createManagedConnection(Principal principal,
ConnectionRequestInfo info)
throws ResourceException {
ManagedConnection connection = _factory.createManagedConnection(
principal, info);
return add(connection, false);
}
/**
* Creates an acceptor for connections.
*
* @param authenticator authenticates incoming connections
* @param info the connection request info
* @return a new connection acceptor
* @throws ResourceException if an acceptor cannot be created
*/
public ManagedConnectionAcceptor createManagedConnectionAcceptor(
Authenticator authenticator, ConnectionRequestInfo info)
throws ResourceException {
ManagedConnectionAcceptor acceptor;
acceptor = _factory.createManagedConnectionAcceptor(authenticator,
info);
_acceptors.add(acceptor);
return acceptor;
}
/**
* Returns a matched connection from the set of pooled connections.
*
* @param principal the security principal
* @param info the connection request info
* @return the first acceptable match, or <code>null</code> if none is
* found
* @throws ResourceException for any error
*/
public ManagedConnection matchManagedConnections(Principal principal,
ConnectionRequestInfo info)
throws ResourceException {
ManagedConnection result;
synchronized (_reapLock) {
// ensure idle connections aren't being reaped while matching
result = _factory.matchManagedConnections(_connections, principal,
info);
if (result != null) {
// return the handle corresponding to the connection
result = (ManagedConnection) _handles.get(result);
} else {
result = _factory.matchManagedConnections(_accepted, principal,
info);
}
}
return result;
}
/**
* Returns a matched acceptor from the set of pooled connections.
*
* @param info the connection request info
* @return the first acceptable match, or <code>null</code> if none is
* found
* @throws ResourceException for any error
*/
public ManagedConnectionAcceptor matchManagedConnectionAcceptors(
ConnectionRequestInfo info) throws ResourceException {
return _factory.matchManagedConnectionAcceptors(_acceptors, info);
}
/**
* Returns a listener for handling accepted connections.
*
* @return a listener for handling accepted connections
*/
public ManagedConnectionAcceptorListener
getManagedConnectionAcceptorListener() {
return this;
}
/**
* Invoked when a new connection is accepted.
*
* @param acceptor the acceptor which created the connection
* @param connection the accepted connection
*/
public void accepted(ManagedConnectionAcceptor acceptor,
ManagedConnection connection) {
try {
add(connection, true);
} catch (ResourceException exception) {
_log.debug("Failed to accept connection", exception);
}
}
/**
* Notifies closure of a connection. The <code>ManagedConnection</code>
* instance invokes this to notify its registered listeners when the peer
* closes the connection.
*
* @param source the managed connection that is the source of the event
*/
public void closed(ManagedConnection source) {
if (_log.isDebugEnabled()) {
_log.debug("Connection " + source + " closed by peer, destroying");
}
remove(source);
}
/**
* Notifies a connection related error. The <code>ManagedConnection</code>
* instance invokes this to notify of the occurrence of a physical
* connection-related error.
*
* @param source the managed connection that is the source of the event
* @param throwable the error
*/
public void error(ManagedConnection source, Throwable throwable) {
if (_log.isDebugEnabled()) {
_log.debug("Error on connection " + source + ", destroying",
throwable);
}
remove(source);
}
/**
* Notifies of a successful ping.
*
* @param source the managed connection that is the source of the event
*/
public void pinged(ManagedConnection source) {
ManagedConnectionHandle handle
= (ManagedConnectionHandle) _handles.get(source);
if (handle != null) {
handle.pinged();
}
}
/**
* Closes this connection pool, cleaning up any allocated resources.
*
* @throws ResourceException for any error
*/
public void close() throws ResourceException {
ManagedConnectionAcceptor[] acceptors =
(ManagedConnectionAcceptor[]) _acceptors.toArray(
new ManagedConnectionAcceptor[0]);
_acceptors.clear();
for (int i = 0; i < acceptors.length; ++i) {
acceptors[i].close();
}
ManagedConnection[] connections =
(ManagedConnection[]) _entries.keySet().toArray(
new ManagedConnection[0]);
for (int i = 0; i < connections.length; ++i) {
connections[i].destroy();
}
_entries.clear();
_accepted.clear();
_connections.clear();
stopReaper();
}
/**
* Invoked when an acceptor receives an error.
*
* @param acceptor the acceptor which received the error
* @param throwable the error
*/
public void error(ManagedConnectionAcceptor acceptor,
Throwable throwable) {
_acceptors.remove(acceptor);
String uri = "<unknown>";
try {
uri = acceptor.getURI().toString();
} catch (ResourceException ignore) {
// no-op
}
_log.error("Failed to accept connections on URI=" + uri,
throwable);
try {
acceptor.close();
} catch (ResourceException exception) {
if (_log.isDebugEnabled()) {
_log.debug("Failed to close acceptor, URI=" + uri, exception);
}
}
}
/**
* Sets the listener for caller events.
*
* @param listener the listener
*/
public void setCallerListener(CallerListener listener) {
_listener = listener;
}
/**
* Notifies when a managed connection is idle.
*
* @param connection the idle connection
*/
protected synchronized void idle(ManagedConnectionHandle connection) {
connection.clearUsed();
if (_daemon != null) {
_daemon.executeAfterDelay(_idlePeriod, new IdleReaper());
}
}
/**
* Adds a connection to the pool. If the connection was created, a {@link
* ManagedConnectionHandle} will be returned, wrapping the supplied
* connection.
*
* @param connection the connection to add
* @param accepted if <code>true</code> the connection was accepted via an
* {@link ManagedConnectionAcceptor}, otherwise it was
* created via
* {@link ManagedConnectionFactory#createManagedConnection}
* @return the (possibly wrapped) connection
* @throws ResourceException if the connection cannot be added
*/
protected ManagedConnection add(ManagedConnection connection,
boolean accepted) throws ResourceException {
ManagedConnection result;
PoolEntry entry = new PoolEntry(connection, accepted);
_entries.put(connection, entry);
if (accepted) {
_accepted.add(connection);
result = connection;
} else {
_connections.add(connection);
ManagedConnection handle = new ManagedConnectionHandle(
this, connection, _resolver);
_handles.put(connection, handle);
result = handle;
}
ContextInvocationHandler handler = new ContextInvocationHandler(
_handler, _resolver, result);
try {
connection.setInvocationHandler(handler);
connection.setConnectionEventListener(this);
} catch (ResourceException exception) {
try {
_log.debug("Failed to initialise connection, destroying",
exception);
connection.destroy();
} catch (ResourceException nested) {
_log.debug("Failed to destroy connection", nested);
} finally {
_entries.remove(connection);
if (accepted) {
_accepted.remove(connection);
} else {
_connections.remove(connection);
_handles.remove(connection);
}
}
// propagate the exception
throw exception;
}
// mark the connection as initialised and therefore available for
// reaping
entry.setInitialised();
startReaper();
return result;
}
/**
* Remove a connection from the pool.
*
* @param connection the connection to remove
*/
protected void remove(ManagedConnection connection) {
PoolEntry entry = (PoolEntry) _entries.remove(connection);
if (entry != null) {
if (entry.getAccepted()) {
_accepted.remove(connection);
} else {
_connections.remove(connection);
_handles.remove(connection);
}
URI remoteURI = null;
URI localURI = null;
try {
remoteURI = connection.getRemoteURI();
localURI = connection.getLocalURI();
} catch (ResourceException exception) {
_log.debug("Failed to get connection URIs", exception);
}
try {
connection.destroy();
} catch (ResourceException exception) {
_log.debug("Failed to destroy connection", exception);
}
if (remoteURI != null && localURI != null) {
notifyDisconnection(remoteURI, localURI);
}
} else {
_log.debug("ManagedConnection not found");
}
if (_entries.isEmpty()) {
stopReaper();
}
}
/**
* Notify of a disconnection.
*
* @param remoteURI the remote address that the client is calling from
* @param localURI the local address that the client is calling to
*/
private void notifyDisconnection(URI remoteURI, URI localURI) {
CallerListener listener = _listener;
if (listener != null) {
listener.disconnected(new CallerImpl(remoteURI, localURI));
}
}
/**
* Starts the reaper for dead/idle connections, if needed.
*/
private synchronized void startReaper() {
if (_daemon == null) {
_daemon = new ClockDaemon();
ThreadFactory creator =
new ThreadFactory(null, "ManagedConnectionReaper", false);
_daemon.setThreadFactory(creator);
if (_reapInterval > 0) {
_daemon.executePeriodically(_reapInterval, new DeadReaper(),
false);
}
}
}
/**
* Stops the reaper for dead/idle connections, if needed.
*/
private synchronized void stopReaper() {
if (_daemon != null) {
_daemon.shutDown();
_daemon = null;
}
}
/**
* Reap idle connections.
*/
private void reapIdleConnections() {
Map.Entry[] entries = (Map.Entry[]) _handles.entrySet().toArray(
new Map.Entry[0]);
for (int i = 0; i < entries.length && !stopReaping(); ++i) {
Map.Entry entry = entries[i];
ManagedConnection connection =
(ManagedConnection) entry.getKey();
PoolEntry pooled = (PoolEntry) _entries.get(connection);
if (pooled != null && pooled.isInitialised()) {
ManagedConnectionHandle handle =
(ManagedConnectionHandle) entry.getValue();
if (handle.canDestroy()) {
if (_log.isDebugEnabled()) {
try {
_log.debug("Reaping idle connection, URI="
+ connection.getRemoteURI()
+ ", local URI="
+ connection.getLocalURI());
} catch (ResourceException ignore) {
// do nothing
}
}
remove(connection);
}
}
}
}
/**
* Reap dead connections.
*/
private void reapDeadConnections() {
Map.Entry[] entries = (Map.Entry[]) _handles.entrySet().toArray(
new Map.Entry[0]);
for (int i = 0; i < entries.length && !stopReaping(); ++i) {
Map.Entry entry = entries[i];
ManagedConnection connection =
(ManagedConnection) entry.getKey();
PoolEntry pooled = (PoolEntry) _entries.get(connection);
if (pooled != null && pooled.isInitialised()) {
ManagedConnectionHandle handle =
(ManagedConnectionHandle) entry.getValue();
if (!handle.used()) {
// if the handle is unused, and is not waiting on a ping
// reply, ping the connection
if (handle.pinging()) {
if (handle.incPingWaits() > _reapDeadIterations) {
remove(connection);
}
} else {
try {
handle.ping();
} catch (ResourceException exception) {
if (_log.isDebugEnabled()) {
try {
_log.debug(
"Failed to ping connection, URI="
+ connection.getRemoteURI()
+ ", localURI="
+ connection.getLocalURI());
} catch (ResourceException ignore) {
// do nothing
}
}
remove(connection);
}
}
} else {
handle.clearUsed();
}
}
}
}
/**
* Helper to determines if a reaper should terminate, by checking the
* interrupt status of the current thread.
*
* @return <code>true</code> if the reaper should terminate
*/
private boolean stopReaping() {
return Thread.currentThread().isInterrupted();
}
/**
* Helper class for reaping idle connections.
*/
private class IdleReaper implements Runnable {
/**
* Run the reaper.
*/
public void run() {
synchronized (_reapLock) {
try {
reapIdleConnections();
} catch (Throwable exception) {
_log.error(exception, exception);
}
}
}
}
/**
* Helper class for reaping dead connections.
*/
private class DeadReaper implements Runnable {
/**
* Run the reaper.
*/
public void run() {
try {
reapDeadConnections();
} catch (Throwable exception) {
_log.error(exception, exception);
}
}
}
}